Special Containment Procedures: At time of acquisition SCP-407 was recorded within a compact cassette tape. Currently, SCP-407 is backed-up as a digital audio file on [DATA EXPUNGED]. SCP-407 should not be allowed to play under any circumstances outside testing conditions, and only with the approval of O5-██.

Testing of SCP-407 is to be done in completely sound-proof environments. All tools and subjects must be sterilized to remove the presence of pollen, fungal spores, plant seeds, and as much bacterial life to the greatest degree possible to delay the negative effects of SCP-407.

Description: SCP-407 is a song in an unidentified language, seemingly sung as a capella. The voices are thought to be human. The tape containing SCP-407 was found with one track of approximately thirty (30) minutes duration, though the abrupt ending suggests there may be more. The song has been described by all listeners as something along the lines of 'soothing', 'glorious', and 'beautiful'.

While SCP-407 is played, rapid cell generation seems to occur within auditory radius. This effect seems to occur at the cellular level, and does not require the subject to be able to hear the music. The changes seem to only affect multi-cellular organisms at first, but quickly begins to affect mitosis in single-celled organisms.

During the first minute of exposure, all multi-cellular life forms seem to become healthier. Subjects suffering from malnutrition, scarring, physical injury, or chronic diseases or other medical conditions seem to become healthy with only a minute of exposure to SCP-407. This has been shown to cure Alzheimer's disease, Crohn's disease, brain and spinal cord injuries, and normally fatal infections or wounds, amongst other things. Interestingly, cancer does not seem to be affected, though the subject's physical condition was still vastly improved.

During the second and third minute of exposure, subjects start experiencing unnecessary unrestrained cell growth, manifesting in quickly advancing dermal growths. These growths seem to mostly be benign tumors and calcium and fat deposits, which though sometimes painful and disfiguring, are not life threatening.

During the fourth minute of exposure, increased bacterial and fungal growth occurs, creating conditions that grow increasingly dangerous for all exposed life, even in their new healthier states. Respiratory and digestive problems are quick to arrive in most cases, and become steadily worse as time progresses.

Past five (5) minutes, the effects of SCP-407 seem to differ each trial. In all cases, trace elements of plants or fungus as well as any animal life present begin to grow and replicate uncontrollably, at varying rates, often shaping into new organisms. Full results have varied depending on the test, and on the objects present when SCP-407 is played.

Addendum-407-01: SCP-407 was found in the home of Professor ██████ of ██████████, who had recently returned from research in the Amazon regions of northern Brazil. Agents were first alerted to a possible SCP when [DATA EXPUNGED]

Addendum 407-02: The mold that eventually resulted from SCP-407's second test appears to be some sort of Cordyceps Fungi. Noted to be similar to mold encountered by SCP-507. Due to fear of fulfilling a fate similar to that observed by 507, testing using SCP-407 has been limited to using only the first twenty (20) minutes of the recording.

Addendum 407-03: Below is a sample test run of SCP-407. For full research and experimentation notes, see Experiment Log 407.Sample Test Notes:<Test 2; SCP-407 played for 28m 32s. Within chamber; 1 D-Class personnel, unsterilized >

00:25 - Subject reports feeling soothed by the music, and of feeling stronger and more invigorated.

00:45 - Liver spots and scars previously seen are shown to disappear.

02:20 - Subject appears to have physically grown an inch. Increase in musculature is noticeable.

03:40 - Subject reports intestinal pain.

04:20 - Subject begins vomiting. From vomit, plants are seen growing and slowly rooting into the tile floor.

06:45 - Subject's body is quickly covered in what is thought to be fungal infections. Plant growth is observed growing from the subject's mouth, then eye sockets.

07:30 - Subject is by this time unrecognizable, covered in molds and plant shoots. Body bursts as a banana tree emerges from the subject's intestines and proceeds to grow to maturity within seconds.

08:45 - Plant and fungal growth has begun to spread throughout the testing chamber. What appears to be moss and weeds cover the floor.

9:30 - Several shoots, stalks, bushes, and even small trees have appeared. Banana tree is no longer recognizable; the tree has grown thick and is covered with foliage and fungal growth.

10:30 - The air is heavy with pollen and spores. Vision into testing chamber is difficult.

11:30 - Movement is heard within the chamber. Several different small insect-like creatures are observed. Creatures are seemingly made of plant matter.

17:30 - For the last six minutes, creatures made of plant matter have been observed to rapidly generate, grow to maturity, kill and eat other creatures, and then be eaten themselves. Creatures increasingly progressing in size as time increases.

21:00 - Large fungal stalk is observed to grow from one of the mammalian creatures. Stalk end bursts, dispensing white spores.

22:00 - Plant growth is still lush, but everything begins to become coated by a layer of mold. The plant creatures seem to die slowly for an unknown reason, before being covered by the mold.

23:00 - Mammalian creatures are the last to succumb; they heavily decay and become covered in the same mold. Bodies are shown to contract and expand as if breathing. Stalks quickly rise from the bodies, burst with spores, and then just as quickly rot.

28:32 - Tape ends. No change in chamber since the appearance of the mold. Chamber undergoes rigorous anti-biological cleansing. Samples of the mold were taken. [See Addenda 407-01, 407-02]

<End Test 2>

Addendum 407-04 SCP-407 has been deleted from the system by what is now known to the Foundation as the Interest Group: Serpent's Hand. All known backup copies of SCP-407 have also been deleted. Refer to Incident Report X23.